The present invention relates to devices for wrapping hay bales with plastic for protection of the hay in the bale from the elements and, more particularly, to a self-propelled vehicle for continuously wrapping and discharging relatively large and cylindrically shaped hay bales.
Large hay bales have become very popular in many regions of the country as one large bale can be handled quite efficiently with the heavy equipment available on most farms, as compared to the very labor intensive work required to handle the many small bales required to feed to livestock to provide the equivalent feed as one large bale.
Initially, the large bales were not protected from the elements, but were stored where they were made or at another outside site. With such outdoor storage, there is normally a spoilage of ten percent or more of the bale due to weathering and mostly due to water damage. To reduce or eliminate this spoilage, farmers have tried to cover or otherwise protect the bales from the weather. However, most of the previous methods used have used materials that are relatively expensive, the methods have been very labor intensive or the methods have been ineffective due to damage to the product or due to failure to adequately protect the bale.
In particular, some prior methods and apparati for covering cylindrical hay bales with plastic have included depositing a bale in a plastic bag or rotating a bale on a turntable and swathing the bale with a sheet of plastic. Both of these methods have disadvantages. Bales are rarely precisely the same shape. Therefore, a plastic bag must be large enough to handle larger bales. If a smaller bale is placed in such a bag, it will tend to catch on other objects, such as the bale handling device, and tear. Bagging individual bales or placing individual bales on a single rotating table are both time consuming processes, requiring the covering of each bale on all sides. In each of these methods, the wrapped bale must usually be moved to another location for storage, increasing the chance of tearing the plastic and exposing the bale to the elements.
It is noted that various methods and mechanisms for generally wrapping cylindrical loads have been utilized for many years. In one such method, a conveyor was used to transport a load to a wrapping mechanism that rotated about the load, covering the load with a plurality of layers of stretched film. A second conveyor then transported the wrapped load away from the wrapping mechanism to a storage location. Such a mechanism has numerous problems when applied to a large hay bale, including that it is difficult with such a device to hold the load during wrapping in such a way as to not interfere with the wrapping process nor damage the load or the wrapping material. Furthermore, such a mechanism does not take into account the special requirements for handling and storing hay bales in a field.
It is also desirable to have a bale wrapping apparatus that is mobile and easily transported to the bales and that is self-propelled during use to avoid the need of having other farm machinery motivate the apparatus while such other machinery may be needed for other purposes.